111-50-2Relevant academic research and scientific papers
Anti-GM1/GD1a complex antibodies in GBS sera specifically recognize the hybrid dimer GM1-GD1a
Mauri, Laura,Casellato, Riccardo,Ciampa, Maria G.,Uekusa, Yoshinori,Kato, Koichi,Kaida, Ken-Ichi,Motoyama, Mayumi,Kusunoki, Susumu,Sonnino, Sandro
, p. 352 - 360 (2012)
It is now emerging the new concept that the antibodies from some patients with Guillain-Barre syndrome (GBS) recognize an antigenic epitope formed by two different gangliosides, a ganglioside complex (GSC). We prepared the dimeric GM1-GD1a hybrid ganglioside derivative that contains two structurally different oligosaccharide chains to mimic the GSC. We use this compound to analyze sera from GBS patients by high-performance thin-layer chromatography immunostaining and enzyme-linked immunosorbent assay. We also synthesized the dimeric GM1-GM1 and GD1a-GD1a compounds that were used in control experiments together with natural gangliosides. The hybrid dimeric GM1-GD1a was specifically recognized by human sera from GBS patients that developed anti-oligosaccharide antibodies specific for grouped complex oligosaccharides, confirming the information that GBS patients developed antibodies against a GSC. High-resolution 1H-13C heteronuclear single-quantum coherence-nuclear overhauser effect spectroscopy nuclear magnetic resonance experiments showed an interaction between the IV Gal-H1 of GM1 and the IV Gal-H2 of GD1a suggesting that the two oligosaccharide chains of the dimeric ganglioside form a single epitope recognized by a single-antibody domain. The availability of a method capable to prepare several hybrid gangliosides, and the availability of simple analytical approaches, opens new perspectives for the understanding and the therapy of several neuropathies. The Author 2011. Published by Oxford University Press. All rights reserved.
Self-assembly, binding, and dynamic properties of heterodimeric porphyrin macrocycles
Ballester, Pablo,Costa, Antoni,Deya, Pere M.,Frontera, Antonio,Gomila, Rosa M.,Oliva, Ana I.,Sanders, Jeremy K. M.,Hunter, Christopher A.
, p. 6616 - 6622 (2005)
A series of heterodimeric tetralactam macrocycles have been self-assembled using two kinetically labile zinc porphyrin-pyridine interactions. The stability constants have been determined by UV-vis titrations in CHCl3. The stability constants depend on the degree of preorganization of the linker units connecting the interacting groups. The ability of the self-assembled macrocycles to bind a terephthalamide guest was also investigated. One of the macrocycles was used for the construction of a [2]rotaxane. The dynamic properties of this system provide insight into the exchange mechanisms that operate in complex noncovalent assemblies.
Nucleating effect and crystal morphology controlling based on binary phase behavior between organic nucleating agent and poly(l-lactic acid)
Fan, Yinqing,Zhu, Jun,Yan, Shifeng,Chen, Xuesi,Yin, Jingbo
, p. 63 - 71 (2015)
A new kind of nucleating agent for poly(l-lactic acid) (PLLA), N,N'-bis(benzoyl) hexanedioic acid dihydrazide (BHAD), was synthesized. Differential scanning calorimetry (DSC), polarization optical microscopy (POM), wide-angle X-ray diffraction (WAXD) and rheometer were used to study the crystallization behavior and crystal morphology of PLLA nucleated by BHAD. In order to ensure the same thermal history of the samples characterized by DSC, POM and XRD, these samples were all thermally treated by DSC. In nonisothermal crystallization, BHAD showed excellent nucleating ability to PLLA. However, it was different from the traditional heterogeneous nucleation mechanism. POM observation showed that morphologies of PLLA crystals varied with the concentration of BHAD and can be classified into three types. Through the systematic investigation of DSC, POM and rheological analysis, it was clearly demonstrated that BHAD had solubility in PLLA matrix, depending on its concentration and processing temperature. Consequently, a highly schematic binary phase diagram of the PLLA/BHAD system was presented, accompanied with a reasonable mechanism of how the PLLA crystal morphologies controlled by BHAD.
Synthesis of Functional Fluorescent BODIPY-based Dyes through Electrophilic Aromatic Substitution: Straightforward Approach towards Customized Fluorescent Probes
Mirri, Giorgio,Schoenmakers, Dani?l C.,Kouwer, Paul H. J.,Verani?, Peter,Mu?evi?, Igor,?tefane, Bogdan
, p. 450 - 454 (2016)
Fluorescent materials are widely used in biological and material applications as probes for imaging or sensing; however, their customization is usually complicated without the support of an organic chemistry laboratory. Here, we present a straightforward method for the customization of BODIPY cores, which are among the most commonly used fluorescent probes. The method is based on the formation of a new C?C bond through Friedel–Crafts electrophilic aromatic substitution carried out at room temperature. The method presented can be used to obtain completely customized fluorescent materials in one or two steps from commercially available compounds. Examples of the preparation of fluorescent materials for cell staining and functionalization of silica colloids are also presented.
New β-phospholactam as a carbapenem transition state analog: Synthesis of a broad-spectrum inhibitor of metallo-β-lactamases
Yang, Ke-Wu,Feng, Lei,Yang, Shao-Kang,Aitha, Mahesh,Lacuran, Alecander E.,Oelschlaeger, Peter,Crowder, Michael W.
, p. 5855 - 5859 (2013)
In an effort to test whether a transition state analog is an inhibitor of the metallo-β-lactamases, a phospholactam analog of carbapenem has been synthesized and characterized. The phospholactam 1 proved to be a weak, time-dependent inhibitor of IMP-1 (70%), CcrA (70%), L1 (70%), NDM-1 (53%), and Bla2 (94%) at an inhibitor concentration of 100 μM. The phospholactam 1 activated ImiS and BcII at the same concentration. Docking studies were used to explain binding and to offer suggestions for modifications to the phospholactam scaffold to improve binding affinities.
Synthesis and opioid receptor binding affinities of 2-substituted and 3-aminomorphinans: Ligands for μ, κ, and δ opioid receptors
Decker, Michael,Si, Yu-Gui,Knapp, Brian I.,Bidlack, Jean M.,Neumeyer, John L.
, p. 402 - 418 (2010)
The phenolic group of the potent μ and κ opioid morphinan agonist/antagonists cyclorphan and butorphan was replaced by phenylamino and benzylamino groups including compounds with parasubstituents in the benzene ring. These compounds are highly potent μ and κ ligands, e.g., p-methoxyphenylaminocyclorphan showing a Ki of 0.026 nMat the μ receptor and a Ki of 0.03 nM at the κ receptor. Phenyl carbamates and phenylureas were synthesized and investigated. Selective o-formylation of butorphan and levorphanol was achieved. This reaction opened the way to a large set of 2-substituted 3-hydroxymorphinans, including 2-hydroxymethyl-, 2-aminomethyl-, and N-substituted 2-aminomethyl-3- hydroxymorphinans. Bivalent ligands bridged in the 2-position were also synthesized and connected with secondary and tertiary aminomethyl groups, amide bonds, and hydroxymethylene groups, respectively. Although most of the 2-substituted morphinans showed considerably lower affinities compared to their parent compounds, the bivalent ligand approach led to significantly higher affinities compared to the univalent 2-substituted morphinans. 2009 American Chemical Society.
Synthetic phosphorylation of p38α recapitulates protein kinase activity
Chooi, K. Phin,Galan, Sebastien R. G.,Raj, Ritu,McCullagh, James,Mohammed, Shabaz,Jones, Lyn H.,Davis, Benjamin G.
, p. 1698 - 1701 (2014)
Through a "tag-and-modify" protein chemical modification strategy, we site-selectively phosphorylated the activation loop of protein kinase p38α. Phosphorylation at natural (180) and unnatural (172) sites created two pure phospho-forms. p38α bearing only a single phosphocysteine (pCys) as a mimic of pThr at 180 was sufficient to switch the kinase to an active state, capable of processing natural protein substrate ATF2; 172 site phosphorylation did not. In this way, we chemically recapitulated triggering of a relevant segment of the MAPK-signaling pathway in vitro. This allowed detailed kinetic analysis of global and stoichiometric phosphorylation events catalyzed by p38α and revealed that site 180 is a sufficient activator alone and engenders dominant mono-phosphorylation activity. Moreover, a survey of kinase inhibition using inhibitors with different (Type I/II) modes (including therapeutically relevant) revealed unambiguously that Type II inhibitors inhibit phosphorylated p38α and allowed discovery of a predictive kinetic analysis based on cooperativity to distinguish Type I vs II.
Synthesis, characterization and biological analysis of transition metal complexes with macro cyclic ligands derived from adipic acid, ethylenediamine with diethyloxalate and diethylmalonate
Nishat, Nahid,Bhat, Shahnawaz Ahmad,Kareem, Abdul,Dhyani, Swati,Mohammad, Abdulrahman,Mirza, Azar Ullah
, p. 395 - 409 (2018)
Macro-cyclic ligands from adipic acid, ethylenediamine with diethyloxalate and diethylmalonate and their respective metal complexes of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) with macro cyclic ligands (LO) and (LM) L [N,N′-bis(2-aminoethyl)hexanediamide] were synthesized successfully. These metal complexes were characterized by Fourier transform infrared, ultraviolet visible spectrometry, proton nuclear magnetic resonance spectroscopy, and mass Spectrometry, CHNS and thermogravimetric analysis. The elemental analysis confirms the structures for Mn(II), Co(II) and Ni(II) complexes similar to octahedral geometry, Cu(II) complexes as a square planar geometry and Zn(II) complexes in the tetrahedral geometry. The molar conductivities of all the metal complexes were taken in 10?3?M DMSO, and values of all the metal complexes showed their electrolytic nature which indicates the presence of chloride ions. Thermal analysis supports as the metal complexes are thermally stable. The result of antimicrobial activity against various microorganisms confirms that the metal complexes are potent bactericides and fungicides than the ligand. Metal complexes of LO with Cu(II) and Zn(II) were found to be highly active against S. typhimurium than the complexes of LM. Graphical abstract: [Figure not available: see fulltext.].
Preliminary studies of a novel cyclopentadienyl tricarbonyl technetium-99m fatty acid derivative for myocardical imaging
Zhang, Hong,Zeng, Huahui,Zhang, Huabei,Wu, Xiangxiang,Chao, Fangfang,Yu, Gang,Zhang, Liqing,Jiang, Han,Liu, Hongbiao,Hou, Haifeng,Zhan, Hongwei,Tian, Mei
, p. 1 - 5 (2013)
This study reports the synthesis and evaluation studies of 6′-cyclopentadienyl tricarbonyl technetium-99m 6′-oxo-11- (hexanamide)undecanoic acid (1). 1 was prepared with 26.5 ± 4.3% of radiochemical yield and more than 98% of radiochemical purity. Tissue distribution in mice showed that high radioactivity accumulated in the heart with moderate clearance. However, unfortunately, similar to those of other technetium-labeled fatty acid analogs, the biodistribution studies of 1 in mice showed poor heart-to-blood ratios, which suggested that 1 cannot be used as myocardial imaging agent, and it may provide a theoretical basis or a lab experience for corresponding fatty acid tracers studies. Tc-99m-labeled fatty acid is very important for the evaluation of myocardial metabolism. 1 was radiolabeled by a double ligand transfer reaction between ferrocene and 99mTc. Amidated 99mTc-labeling fatty acid is beneficial to prolonging retention in myocardium. Copyright
Chemoenzymatic Synthesis of Thiazolyl Peptide Natural Products Featuring an Enzyme-Catalyzed Formal [4 + 2] Cycloaddition
Wever, Walter J.,Bogart, Jonathan W.,Baccile, Joshua A.,Chan, Andrew N.,Schroeder, Frank C.,Bowers, Albert A.
, p. 3494 - 3497 (2015)
Thiocillins from Bacillus cereus ATCC 14579 are members of the well-known thiazolyl peptide class of natural product antibiotics, the biosynthesis of which has recently been shown to proceed via post-translational modification of ribosomally encoded precursor peptides. It has long been hypothesized that the final step of thiazolyl peptide biosynthesis involves a formal [4 + 2] cycloaddition between two dehydroalanines, a unique transformation that had eluded enzymatic characterization. Here we demonstrate that TclM, a single enzyme from the thiocillin biosynthetic pathway, catalyzes this transformation. To facilitate characterization of this new class of enzyme, we have developed a combined chemical and biological route to the complex peptide substrate, relying on chemical synthesis of a modified C-terminal fragment and coupling to a 38-residue leader peptide by means of native chemical ligation (NCL). This strategy, combined with active enzyme, provides a new chemoenzymatic route to this promising class of antibiotics.
